At present, the WLAN network adopts a star architecture with base station+ base station controller, that is a wireless access controller (AP+AC). When the terminal hands over between the APs, the AC is responsible for maintaining identity information of the terminal and performing handover on the data channel of the terminal. And the AC or border router/broadband remote access server (BRAS) is responsible for data forwarding.
With the deployment of 802.11ac products, the air interface rate will go into the 1 Gbps era, if it continues to use the start architecture with AP+AC, one AC is generally responsible for managing dozens of to thousands of APs, the AC is under the pressure of huge data forwarding, so that the requirements for the routing performance and forwarding performance of AC are high, which will become a data bottleneck. Since the border router/BRAS work on the layer 3, and undertake a lot of works such as user attribute management, so that the forwarding efficiency is low, and the cost is high. At the same time, switches and routers with high performances are required by the bearer network to transmit data. Thus, the service network and bearer network form two superimposed networks, such superimposed architecture not only increases the forwarding delay, management complexity and failure probability, but also improves the costs of the network construction and maintenance.